A credit score is used by credit agencies (such as mortgage companies and banks) to assess the creditworthiness of individuals. Values range from 300 to 850, with a credit score over 700 considered to be a quality credit risk. According to a survey, the mean credit score is

704.5.

A credit analyst wondered whether high-income individuals (incomes in excess of $100,000 per year) had higher credit scores. He obtained a random sample of

40

high-income individuals and found the sample mean credit score to be

715.8

with a standard deviation of

80.3.

Conduct the appropriate test to determine if high-income individuals have higher credit scores at the

=0.05

level of significance.

State the null and alternative hypotheses.

H0:

not equals

equals=

greater than>

less than<

nothing

H1:

not equals

equals=

greater than>

less than<

nothing

(Type integers or decimals. Do not round.)

Identify the t-statistic.

t0=nothing

(Round to two decimal places as needed.)

Identify the P-value.

P-value=nothing

(Round to three decimal places as needed.)

Make a conclusion regarding the hypothesis.

Reject

the null hypothesis. There

is not

sufficient evidence to claim that the mean credit score of high-income individuals is

greater than

704.5704.5.